Rf safety system

ABSTRACT

An RF safety system controls antenna radiation based on antenna states determined at least in part by one or more of the antenna orientation, position, and/or acceleration.

PRIORITY CLAIM

This application is a continuation of U.S. App. No. 16/865,594 filed May4, 2020 and entitled RF Shut Down.

BACKGROUND OF THE INVENTION

Emissions of Radio Frequency (RF) energy (RF Radiation) are common. Forexample, every antenna used to transmit radio signals is a source of RFradiation.

Human exposure to, and danger from, RF radiation generally depends uponhow close the source is to our physical bodies. For example, thisproximity may be more important than the power level (or wattage) of theradiation. This is because RF Radiation dissipates with distance. Forexample, low powered exposure next to a person can be more dangerousthan a more powerful exposure at a distance.

Because the distance from an RF source to a person determines RFradiation intensity, potential harm from an RF transmission is reducedby distance from the source. It is for this reason that antennastransmitting RF signals at high powers are located away from people.These antennas may be mounted atop a building, mast, or structure toassure an adequate separation distance is maintained.

Cell phone communications illustrate the use of RF signals. Here, it iscommon for the cell phone to exchange signals with a cell or antennatower (“tower” or “mast”). Tower transmission power, such as 5G networkstransmissions, may reach or exceed 100 watts and the distance betweentowers may be on the order of one or a few city blocks.

Field of Invention

This invention relates to the electrical and electronic arts. Inparticular, the invention provides RF signal control to control antennaradiation.

Discussion of the Related Art

Transmission of RF signals from antennas generally requires a signalthat passes through a transmitter before reaching the antenna. Signaltransmission from such systems is generally controlled by transmitter ortransceiver operation. For example, if electric power supplying thetransmitter is interrupted, then the signal transmitted by the antennais interrupted.

SUMMARY OF THE INVENTION

The present invention provides an RF safety system. In an embodiment,the RF safety system comprises: An antenna fixed above the ground; anantenna state determined at least in part by one or more of an antennaorientation, position, and/or acceleration; and, control of antennaradiation dependent at least in part on the antenna state.

In an embodiment, the RF safety system comprises a sensor that indicatesone or more of antenna orientation, position, and/or acceleration.

In an embodiment the RF safety system wherein sensor data is used tofind a safe distance between the antenna and bystanders.

In an embodiment the RF safety system comprises a structure thatincludes the antenna and a vertical construct for holding the antennaaloft.

In an embodiment the RF safety system wherein the sensor is mounted onthe structure.

In an embodiment, the RF safety comprises: a power supply for supplyingan RF signal source; the RF signal source for driving the antenna toradiate; and, an electrical circuit between the power supply and theantenna for controlling antenna radiation.

In an embodiment, the RF safety system wherein the electrical circuit isbetween the RF signal source and the antenna.

In an embodiment, the RF safety system wherein the electrical circuitacts as a switch.

In an embodiment, the RF safety system wherein RF signals for drivingthe antenna to radiate are controlled at least in part based oninclination of the structure.

In an embodiment, the RF safety system wherein either of a sudden impactto the structure or collapse of the structure results in no RF signalsreaching the antenna and no radiation from the antenna.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is described with reference to the accompanyingfigures. These figures, incorporated herein and forming part of thespecification, illustrate embodiments of the present invention and,together with the description, further serve to explain the principlesof the invention and to enable a person skilled in the relevant art tomake and use the invention.

FIGS. 1A-B shows transmission towers or poles and related equipment inaccordance with the present invention.

FIGS. 2A-B show a mast for use with the equipment of FIG. 1.

FIGS. 3A-B show a sensor package for use with the equipment of FIG. 1.

FIGS. 4A-B show electrical block diagrams typical of the equipment ofFIG. 1.

FIGS. 5A-B show a first tilt sensor and optional visual indicator foruse with the equipment of FIG. 1.

FIGS. 6A-B show a second tilt sensor and optional visual indicator foruse with the equipment of FIG. 1.

FIGS. 7A-B show a tilt switch and optional visual indicator for use withthe equipment of FIG. 1.

FIGS. 8A-C show various inclinations of a sensor for use with theequipment of FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The disclosure provided in the following pages describes examples ofsome embodiments of the invention. The designs, figures, anddescriptions are non-limiting examples of certain embodiments of theinvention. For example, other embodiments of the disclosed device may ormay not include the features described herein. Moreover, disclosedadvantages and benefits may apply to only certain embodiments of theinvention and should not be used to limit the disclosed inventions.

As used herein, coupled means directly or indirectly connected by asuitable means known to persons of ordinary skill in the art. Coupleditems may include interposed features such as, for example, A is coupledto C via B. Unless otherwise stated, the type of coupling, whether it bemechanical, electrical, fluid, optical, radiation, or other is providedby the context in which the term is used.

FIG. 1A shows a transmission tower or pole and related equipment 100A.In the figure, a pole or tower 101 supports an antenna(s) 102. An RFsource or transmitter/transceiver 105 within an electronics cabinet 104(such as a ground mounted electronics cabinet) drives the antenna via afirst communications line 116 such as an electrical cable(s) orwaveguide. Notably, any of the cables mentioned herein may be one ormultiple cables and may incorporate metal conductors and/or opticalconductors. The cable(s) may be hybrid cable such as a cable includingelectrical conductors and optical conductors.

Mounted to and/or moving with the pole/tower 101 or antenna 102 is asensor or sensor package 120. The sensor package may be interconnectedwith any of the transmitter/transceiver, to a wireless communicationssystem, or to another signaling system. In some embodiments sensorinformation or information derived therefrom is made available tooperators of a CATV system, a utility system, or a telephone system. Asshown, the sensor package is interconnected with the electronics cabinet104 via a second communications line 118 such as an electrical cable(s).

The sensor package senses or is used to sense a pole/tower 101 orantenna 102 orientation, position, or impact. For example, the sensorpackage may indicate a proper or improper antenna location.

As seen in the figure, a person 160 stands at a distance “d” below theantenna 102. This distance “d” that separates the person from antenna RFemissions should be adequate to protect the person from the deleteriouseffects of antenna RF emissions. This distance may be referred to as a“safe” distance. In some embodiments, antenna height may be used todetermine the tilt allowable to maintain a safe distance and sensorcontrols may allow an antenna height input to determine this tilt value.In some embodiments, antenna power may be used to determine a safedistance and sensor controls may allow an antenna power input todetermine this safe distance.

Where the structure or its equipment are impacted, tolerableaccelerations, velocities, and positions of the structure or itsequipment may be derived from the item most susceptible to impact, forexample the acceleration of the antenna. Tolerable accelerations,velocities, and positions of the structure or its equipment may also bederived from operating experience.

FIG. 1B shows a transmission tower or pole and related equipment 100B.In the figure, a pole or tower 151 supports an antenna(s) 152. An RFsource or transmitter/transceiver 155 mounted to the tower or pole 151drives the antenna 152. This signal driving the antenna may pass throughan interface 153 between the RF source and the antenna such as a signalconditioning interface.

The transmitter/transceiver 155 may be connected to a power sourceand/or a signal source via a cable or cables such as those shown 180,184. Cable 180 may be attached to an exterior surface of the tower orpole 151. Cable 184 may pass through an interior of the pole.

Mounted to and/or moving with the tower or pole 151 or antenna 152 is asensor or sensor package 120. The sensor package may be interconnectedwith any of the transmitter/transceiver, to a wireless communicationssystem, or to another signaling system. In some embodiments sensorinformation or information derived therefrom is made available tooperators of a CATV system, a utility system, or a telephone system. Asshown, a cable 168 from the sensors is available for any suchconnection.

The sensor package senses or is used to sense a pole/tower 151 orantenna 152 orientation, position, or impact. For example, the sensorpackage may indicate a proper or improper antenna location.

As seen in the figure, a person 160 stands at a distance “d” below theantenna 152. This distance “d” that separates the person from antenna RFemissions should be adequate to protect the person from the deleteriouseffects of antenna RF emissions. This distance may be referred to as a“safe” distance. In some embodiments, antenna height may be used todetermine the tilt allowable to maintain a safe distance and sensorcontrols may allow an antenna height input to determine this tilt value.In some embodiments, antenna power may be used to determine a safedistance and sensor controls may allow an antenna power input todetermine this safe distance.

Where the structure or its equipment are impacted, tolerableaccelerations, velocities, and positions of the structure or itsequipment may be derived from the item most susceptible to impact, forexample the acceleration of the antenna. Tolerable accelerations,velocities, and positions of the structure or its equipment may also bederived from operating experience.

FIG. 2A shows a structure with an antenna(s) mounted atop an antennamast such as an elongated structure, pole, or tower 200A.

An antenna mast 201 is supported by mast base 230. In variousembodiments, the mast base may be attached to a concrete or other pad240 as shown. In various embodiments, the mast may be an elongatedmember(s) extending from the base. One or more of the mast members maybe metallic, concrete, wood, and/or composite. As mentioned above, atransmitter/transceiver for interconnection with the antenna may bemounted on the mast.

A sensor package 220 is affixed to the mast 201. For example, the sensorpackage may be attached directly or indirectly to the mast. For example,the sensor package may be attached below the antenna(s) (as shown). Anelectrical cable 218 extends from the sensor package. The electricalcable may be routed to tower electrical systems such as to anelectronics cabinet 104.

FIG. 2B shows a failed antenna mast 200B. Notably, failure of theantenna mast 201, base 230, or antenna 202 may occur in differentlocations and may be due to many different causes. For example, thestructure 200A may be subject to an automobile or other strike, winddamage, earthquake damage, and the like. Whatever the case, a failure ofthe structure 200A results in a change antenna 202 orientation orposition.

A typical failure of the structure 200A results when the mast 201 isstruck by a moving object such as an automobile. This strike may bend orbreak 245 the mast 201 such that a normally upright antenna 202 is nolonger upright but tilts toward a surface 250 or the ground 260.

Where the sensor package 220 is mounted to move with the mast or anupper portion of the mast 221, a sufficiently failed mast that tiltstoward the ground 260 results in a misoriented sensor package.

FIGS. 3A-B show a sensor package 300A-B using plan and perspectiveviews. The sensor package may include a box 301 that houses the sensor302. The package may further include a visual indicator 304 such as anLED indicator. Where a visual indicator is used, the box may include atranslucent cover 320 through which the visible indicator may be seen.

An electrical cable in a protective cover 306 extends from the sensor.The electrical cable may be routed to tower electrical systems such asto an electronics cabinet 104.

As mentioned above, a sensor package 220 may sense impact, tilting,misorientation, or acceleration of an antenna or its supporting mast,for example misorientation of the antenna 202 or its supporting mast201. Various sensor may be used for this purpose including tilt sensors,inclinometers, orientation sensors, altitude sensors, misorientationsensors, and accelerometers. In some embodiments sensors include one ormore of mechanical, mercury or powered tilt sensors or switches. In someembodiments sensors include an impact sensor similar to an airbag sensoror crash sensor.

The visual indicator may be visible from a distance such that it isviewable from the ground or from locations nearby. Indicator color maybe used to indicate various sensor measurements or information derivedtherefrom. For example, red may indicate trouble while green mayindicate no trouble. Indicator flash sequences may be used to indicatevarious sensor measurements or information derived therefrom. Forexample, quick flashes may indicate one state while slow flashes mayindicate another state.

FIGS. 4A-B show electrical block diagrams including the antenna, sensor,and interconnecting circuitry 400A-B.

In FIG. 4A, a housing such as an electrical cabinet 104 may enclose anRF signal source 404, a power supply for the RF signal source 406, and aswitch 408 for interrupting delivery of the RF signal to the antenna.Interconnecting with this equipment is a sensor 302 or sensor package220 and an antenna 202 supported by a mast 201. In some embodiments line411 is for transporting signals from the sensor to the electronicscabinet 140 and/or the switch 408.

Line 410 is for transporting the RF signal to the antenna 202. Theelectrical signal for driving the antenna 202 may be interrupted whenthe power supplying the RF signal source is interrupted or when thesignal carried by line 410 is otherwise interrupted. For example, usingthe switch 408 controlled by the sensor 302 or a similar means tointerrupting the power required to operate the RF signal source endssignal transmission via line 410 to the antenna. For example, using theswitch 408 controlled by the sensor or a similar means to interrupt thesignal from the RF signal source and normally transported by line 410ends signal transmission via line 410 to the antenna.

In FIG. 4B a housing such as an electrical cabinet 104 may enclose an RFsignal source 404, a power supply for the RF signal source 406, and aswitch 408 for interrupting delivery of the RF signal to the antenna.Interconnecting with this equipment is a sensor 302 or sensor package220 and an antenna 202 supported by a mast 201. Line 450 is fortransporting signals from the sensor 302 to the switch 408.

Line 440 is for transporting the RF signal to the antenna 202. Theelectrical signal for driving the antenna 202 may be interrupted whenthe power supplying the RF signal source is interrupted. For example,using the switch 408 controlled by the sensor to interrupt the powerrequired to operate the RF signal source ends signal transmission vialine 440 to the antenna.

FIGS. 5A-B show a first tilt sensor and optional visual indicator500A-B. FIG. 5A shows the tilt sensor 302 oriented in an uprightposition while FIG. 5B shows a tilt sensor that is not oriented in anupright position.

The tilt sensor 302 may be in a powered circuit such as a two wirecircuit 540, 550 interconnecting directly or indirectly with switch 408.The tilt sensor may utilize dry contacts in a two wire circuit 540, 550interconnecting directly or indirectly with switch 408.

In some embodiments, a tilt signal indicating a proper antenna 202orientation or position results in switch 408 powering the RF signalsource 404. In some embodiments, a tilt signal indicating improperorientation or position results in switch 408 not powering RF signalsource 404.

An optional visual indicator such as LED 304 may be used to indicate thepresence/availability of electrical power. Where the tilt sensor is in apowered circuit, the indicator may be connected with the two wirecircuit 540, 550 or in series with one the conductors 540, 550. Wherethe tilt sensor is not in a powered circuit, yet another pair of wires540, 550 may be used to power the LED.

FIGS. 6A-B show a second tilt sensor and series connected optionalvisual indicator 600A-B. FIG. 6A shows the tilt sensor 302 oriented inan upright position while FIG. 6B shows a tilt sensor that is notoriented in an upright position.

Here, the tilt sensor and LED are in a series circuit 540, 550 thatinterconnects directly or indirectly with the switch 408. Notably, thecircuit 540, 550 may connect in series or otherwise with the switch.

In some embodiments, a tilt signal indicating a proper antenna 202orientation or position results in switch 408 powering the RF signalsource 404. In some embodiments, a tilt signal indicating improperorientation or position results in switch 408 not powering RF signalsource 404.

FIGS. 7A-B shows a tilt switch (off/on) and series connected optionalvisual indicator 700A-B. In this embodiment, FIG. 7A shows the tiltswitch 302 in the closed position indicating the antenna is orientedand/or positioned properly such that the antenna 202 receives a signalfrom the RF signal source 404. Here, the circuit 540, 550 is completedand the LED 340 is illuminated. Alternatively, the switch might be opento indicate the antenna is oriented and or positioned properly such thatthe antenna 202 receives a signal from the RF signal source 404.

FIG. 7B shows a tilt switch 302 in the open position indicating theantenna is oriented and/or positioned improperly such that the antenna202 does not receive a signal from the RF signal source 404.Alternatively, the switch might be closed to indicate the antenna isoriented and or positioned properly such that the antenna 202 receives asignal from the RF signal source 404.

Each of FIGS. 8A-C show a front view and side view of the sensor packagein various orientations or positions 800A-C.

FIG. 8A shows the sensor package 220 as it might be oriented orpositioned when the mast 201 (see FIG. 2A) is upright at 0 degrees withthe vertical. In this configuration, the sensor 302 is oriented forproper operation of the antenna.

FIG. 8B shows the sensor package 220 as it might be oriented orpositioned when the mast 201 leans to one side, for example at an angleof up to 30 degrees. In this configuration, the sensor 302 is orientedfor proper operation of the antenna. Notably, this range of 0+ degreesto 30 degrees may be varied to suit mast height and/or allowabledistances from the antenna to a person below. For example, the range maybe from 0 degrees to 10 degrees, from 0 degrees to 20 degrees, from 0degrees to 40 degrees, or from 0 degrees to 45 degrees.

FIG. 8C shows the sensor package 220 as it might be oriented orpositioned when the mast 201 leans to one side, for example at an anglegreater than 30 degrees. In this configuration, the sensor 302 is notoriented for proper operation of the antenna. Notably, this range ofgreater than 30 degrees may be varied to suit mast height and/orallowable distances from the antenna to a person below. For example, therange may be angles of lean greater than 5 degrees, greater than 10degrees, greater than 20 degrees, greater than 40 degrees, and greaterthan 45 degrees.

As explained above, the RF safety system may prevent potentiallydangerous reductions in the distance separating the antenna 202 andpersons below when the mast 201 is oriented or positioned improperly.

While various embodiments of the present invention have been describedabove, it should be understood that they have been presented by way ofexample only, and not limitation. It will be apparent to those skilledin the art that various changes in the form and details can be madewithout departing from the spirit and scope of the invention. As such,the breadth and scope of the present invention should not be limited bythe above-described exemplary embodiments, but should be defined only inaccordance with the following claims and equivalents thereof.

What is claimed is:
 1. An RF safety system comprising: an antenna fixedabove the ground; an antenna state determined at least in part by one ormore of an antenna orientation, position, and/or acceleration; and,control of antenna radiation dependent at least in part on the antennastate.
 2. The RF safety system of claim 1 further comprising a sensorthat indicates one or more of antenna orientation, position, and/oracceleration.
 3. The RF safety system of claim 2 wherein sensor data isused to find a safe distance between the antenna and bystanders.
 4. TheRF safety system of claim 2 further comprising a structure that includesthe antenna and a vertical construct for holding the antenna aloft. 5.The RF safety system of claim 4 wherein the sensor is mounted on thestructure.
 6. The RF safety system of claim 5 further comprising: apower supply for supplying an RF signal source; the RF signal source fordriving the antenna to radiate; and, an electrical circuit between thepower supply and the antenna for controlling antenna radiation.
 7. TheRF safety system of claim 6 wherein the electrical circuit is betweenthe RF signal source and the antenna.
 8. The RF safety system of claim 7wherein the electrical circuit acts as a switch.
 9. The RF safety systemof claim 1 wherein RF signals for driving the antenna to radiate arecontrolled at least in part based on inclination of the structure. 10.The RF safety system of claim 1 wherein either of a sudden impact to thestructure or collapse of the structure results in no RF signals reachingthe antenna and no radiation from the antenna.